Oki N, Awa S
Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan.
Acta Paediatr Jpn. 1995 Aug;37(4):450-7. doi: 10.1111/j.1442-200x.1995.tb03354.x.
There is a paucity of knowledge regarding right coronary pulsatile hemodynamics when the right ventricle is under hemodynamic overload as is often the case in pediatric patients with congenital cardiac anomalies. To elucidate the exact mechanisms for the right coronary artery (RCA) to cope with the overload, we studied nine open-chest adult Beagles and analyzed the flow signals of the RCA in relation to independently varied heart rate (pacing) and right ventricular pressure (pulmonary artery banding). Both increased heart rate and right ventricular pressure increased the total volume flow of the RCA. The diastolic over total flow ratio (D/T), however, enlarged on increasing right ventricular pressures while it declined on increasing heart rates. Our data confirmed, as well, that increased flow of RCA on rising heart rate was provided mainly by an increase in systolic phase, while the increase on augmented right ventricular pressure was provided by the increase in diastolic phase. The RCA manages to deliver blood to the right ventricular musculature in two different ways in response to increasing heart rate and right ventricular pressure.
对于右冠状动脉的搏动性血流动力学，当右心室处于血流动力学过载状态时（先天性心脏畸形的儿科患者常常如此），我们所知甚少。为了阐明右冠状动脉（RCA）应对过载的确切机制，我们研究了9只开胸成年比格犬，并分析了RCA的血流信号与独立变化的心率（起搏）和右心室压力（肺动脉束带）之间的关系。心率增加和右心室压力增加均会使RCA的总血流量增加。然而，舒张期与总流量之比（D/T）在右心室压力增加时增大，而在心率增加时减小。我们的数据还证实，心率上升时RCA血流量的增加主要由收缩期增加所致，而右心室压力升高时血流量的增加则由舒张期增加所致。RCA通过两种不同方式设法在心率增加和右心室压力增加时将血液输送至右心室肌肉组织。
